An inlet tap can fill water at the rate of 20 litres per minute. Now, before opening the inlet tap they found a leak in the tank which can empty the tank in 8 hours. They could not repair the leak and opened the inlet tap when the tank was full and it empties the tank in 10 hours. Find the capacity of tank.

An inlet tap can fill water at the rate of 20 litres per minute. Now, before opening the inlet tap they found a leak in the tank which can empty the tank in 8 hours. They could not repair the leak and opened the inlet tap when the tank was full and it empties the tank in 10 hours. Find the capacity of tank. Correct Answer 48000 litres

Given:

Flow of inlet tap per minute = 20 litres

Leak can empty the tank in 8 hours

If the inlet tap is opened and leak is also there then it empties the tank in 10 hours

Concept used:

Work = Time taken × efficiency

And, efficiency of emptying taps is taken in negative

Calculation used:

Let the total work be x

Leak can empty the tank in 8 hours

Efficiency of leak = -x/8

Leak with inlet tap can empty the tank in 10 hours

Efficiency of leak with inlet tap = -x/10

Now efficiency of inlet tap = -x/10 – (-x/8) = -x/10 + x/8

⇒ Efficiency of inlet tap = x/40

Now the time taken by inlet tap = (x ÷ x/40)

⇒ Time taken by inlet tap = 40 hours = 2400 minutes

Total capacity of tank = (2400 × 20) litres

⇒ Total capacity of tank = 48000 litres

∴ The capacity of the tank is 48000 litres

 Confusion Points Flow of inlet tap per minute = 20 litres

We have multiplied by 60 to make Flow of inlet tap per hour.

Related Questions

The following questions have three statements. Study the question and the statements and decide which of the statement(s) is/are necessary to answer the question. In how many hours tap B can fill the completely empty tank? Statement I: The inlet tap A and the outlet tap C working simultaneously takes 40 hours to fill the tank. Statement II: Efficiency of inlet tap B is equal to efficiency of outlet tap C or 62.5% of the efficiency of inlet tap A. Statement III: The outlet tap C can empty a half filled tank in 12 hours.